package cn.com.yyg.front.utils;  
  
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
  
public class FileTypeUtils  
{  
    public final static Map<String, String> FILE_TYPE_MAP = new HashMap<String, String>();  
      
    private FileTypeUtils(){}  
    static{  
        getAllFileType();  //初始化文件类型信息  
    }  
      
    /** 
     * Created on 2010-7-1  
     * <p>Discription:[getAllFileType,常见文件头信息]</p> 
     * @author:[shixing_11@sina.com] 
     */  
    private static void getAllFileType()  
    {  
        FILE_TYPE_MAP.put("jpg", "FFD8FF"); //JPEG (jpg)  
        FILE_TYPE_MAP.put("png", "89504E47");  //PNG (png)  
        FILE_TYPE_MAP.put("gif", "47494638");  //GIF (gif)  
        FILE_TYPE_MAP.put("tif", "49492A00");  //TIFF (tif)  
        FILE_TYPE_MAP.put("bmp", "424D"); //Windows Bitmap (bmp)  
        FILE_TYPE_MAP.put("dwg", "41433130"); //CAD (dwg)  
        FILE_TYPE_MAP.put("html", "68746D6C3E");  //HTML (html)  
        FILE_TYPE_MAP.put("rtf", "7B5C727466");  //Rich Text Format (rtf)  
        FILE_TYPE_MAP.put("xml", "3C3F786D6C");  
        FILE_TYPE_MAP.put("zip", "504B0304");  
        FILE_TYPE_MAP.put("rar", "52617221");  
        FILE_TYPE_MAP.put("psd", "38425053");  //Photoshop (psd)  
        FILE_TYPE_MAP.put("eml", "44656C69766572792D646174653A");  //Email [thorough only] (eml)  
        FILE_TYPE_MAP.put("dbx", "CFAD12FEC5FD746F");  //Outlook Express (dbx)  
        FILE_TYPE_MAP.put("pst", "2142444E");  //Outlook (pst)  
        FILE_TYPE_MAP.put("xls", "D0CF11E0");  //MS Word  
        FILE_TYPE_MAP.put("doc", "D0CF11E0");  //MS Excel 注意：word 和 excel的文件头一样  
        FILE_TYPE_MAP.put("mdb", "5374616E64617264204A");  //MS Access (mdb)  
        FILE_TYPE_MAP.put("wpd", "FF575043"); //WordPerfect (wpd)   
        FILE_TYPE_MAP.put("eps", "252150532D41646F6265");  
        FILE_TYPE_MAP.put("ps", "252150532D41646F6265");  
        FILE_TYPE_MAP.put("pdf", "255044462D312E");  //Adobe Acrobat (pdf)  
        FILE_TYPE_MAP.put("qdf", "AC9EBD8F");  //Quicken (qdf)  
        FILE_TYPE_MAP.put("pwl", "E3828596");  //Windows Password (pwl)  
        FILE_TYPE_MAP.put("wav", "57415645");  //Wave (wav)  
        FILE_TYPE_MAP.put("avi", "41564920");  
        FILE_TYPE_MAP.put("ram", "2E7261FD");  //Real Audio (ram)  
        FILE_TYPE_MAP.put("rm", "2E524D46");  //Real Media (rm)  
        FILE_TYPE_MAP.put("mpg", "000001BA");  //  
        FILE_TYPE_MAP.put("mov", "6D6F6F76");  //Quicktime (mov)  
        FILE_TYPE_MAP.put("asf", "3026B2758E66CF11"); //Windows Media (asf)  
        FILE_TYPE_MAP.put("mid", "4D546864");  //MIDI (mid)  
    }  
  
    public static void main(String[] args) throws Exception  
    {  
        File f = new File("c://aaa.gif");  
        if (f.exists())  
        {  
            String filetype1 = getImageFileType(f);  
            System.out.println(filetype1);  
            String filetype2 = getFileByFile(f);  
            System.out.println(filetype2);  
        }  
    }  
  
    /** 
     * Created on 2010-7-1  
     * <p>Discription:[getImageFileType,获取图片文件实际类型,若不是图片则返回null]</p> 
     * @param File 
     * @return fileType 
     * @author:[shixing_11@sina.com] 
     */  
    public final static String getImageFileType(File f)  
    {  
        if (isImage(f))
        {
            try
            {
                ImageInputStream iis = ImageIO.createImageInputStream(f);
                Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);
                if (!iter.hasNext())
                {
                    return null;
                }
                ImageReader reader = iter.next();
                iis.close();
                return reader.getFormatName();
            }
            catch (IOException e)
            {
                return null;
            }
            catch (Exception e)
            {
                return null;
            }
        }
        return null;
    }  
  
    /** 
     * Created on 2010-7-1  
     * <p>Discription:[getFileByFile,获取文件类型,包括图片,若格式不是已配置的,则返回null]</p> 
     * @param file 
     * @return fileType 
     * @author:[shixing_11@sina.com] 
     */  
    public final static String getFileByFile(File file)  
    {  
        String filetype = null;  
        byte[] b = new byte[50];  
        try  
        {  
            InputStream is = new FileInputStream(file);  
            is.read(b);  
            filetype = getFileTypeByStream(b);  
            is.close();  
        }  
        catch (FileNotFoundException e)  
        {  
            e.printStackTrace();  
        }  
        catch (IOException e)  
        {  
            e.printStackTrace();  
        }  
        return filetype;  
    }  
      
    /** 
     * Created on 2010-7-1  
     * <p>Discription:[getFileTypeByStream]</p> 
     * @param b 
     * @return fileType 
     * @author:[shixing_11@sina.com] 
     */  
    public final static String getFileTypeByStream(byte[] b)  
    {  
        String filetypeHex = String.valueOf(getFileHexString(b));  
        Iterator<Entry<String, String>> entryiterator = FILE_TYPE_MAP.entrySet().iterator();  
        while (entryiterator.hasNext()) {  
            Entry<String,String> entry =  entryiterator.next();  
            String fileTypeHexValue = entry.getValue();  
            if (filetypeHex.toUpperCase().startsWith(fileTypeHexValue)) {  
                return entry.getKey();  
            }  
        }  
        return null;  
    }  
      
    /**
     * Created on 2010-7-2 
     * <p>Discription:[isImage,判断文件是否为图片]</p>
     * @param file
     * @return true 是 | false 否
     * @author:[shixing_11@sina.com]
     */
    public static final boolean isImage(File file){
        boolean flag = false;
        try
        {
            BufferedImage bufreader = ImageIO.read(file);
            int width = bufreader.getWidth();
            int height = bufreader.getHeight();
            if(width==0 || height==0){
                flag = false;
            }else {
                flag = true;
            }
        }
        catch (IOException e)
        {
            flag = false;
        }catch (Exception e) {
            flag = false;
        }
        return flag;
    }
    
    /** 
     * Created on 2010-7-1  
     * <p>Discription:[getFileHexString]</p> 
     * @param b 
     * @return fileTypeHex 
     * @author:[shixing_11@sina.com] 
     */  
    public final static String getFileHexString(byte[] b)  
    {  
        StringBuilder stringBuilder = new StringBuilder();  
        if (b == null || b.length <= 0)  
        {  
            return null;  
        }  
        for (int i = 0; i < b.length; i++)  
        {  
            int v = b[i] & 0xFF;  
            String hv = Integer.toHexString(v);  
            if (hv.length() < 2)  
            {  
                stringBuilder.append(0);  
            }  
            stringBuilder.append(hv);  
        }  
        return stringBuilder.toString();  
    }  
}
